What does measurement error indicate in test results?

• A. The test measures what it intends to.
• B. The observed score deviates from the true score.
• C. The test yields the same score across times.
• D. The test is valid for group only.

Answer: (B)

In test theory, the observed score is made up of two parts: the true score (what the test aims to measure) and measurement error (random factors that distort the result). Measurement error indicates how far the observed score is from the true score. If the error is small, the observed score closely reflects the actual ability or trait; if the error is large, the observed score can be quite different from the true score because of random influences like momentary fatigue, misreading items, or scoring inconsistencies. This concept is central to understanding reliability (consistency of scores) and validity (whether the test measures what it’s supposed to), but the specific meaning of measurement error is the discrepancy between what is observed and what is truly present.